US20010055135A1 - Optical network element - Google Patents

Optical network element Download PDF

Info

Publication number
US20010055135A1
US20010055135A1 US09/810,226 US81022601A US2001055135A1 US 20010055135 A1 US20010055135 A1 US 20010055135A1 US 81022601 A US81022601 A US 81022601A US 2001055135 A1 US2001055135 A1 US 2001055135A1
Authority
US
United States
Prior art keywords
optical
network element
multiplex
digital signal
multiplexed
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US09/810,226
Other languages
English (en)
Inventor
Rainer Sigloch
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Alcatel Lucent SAS
Original Assignee
Alcatel SA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Alcatel SA filed Critical Alcatel SA
Assigned to ALCATEL reassignment ALCATEL ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: SIGLOCH, RAINER
Publication of US20010055135A1 publication Critical patent/US20010055135A1/en
Abandoned legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J3/00—Time-division multiplex systems
    • H04J3/02—Details
    • H04J3/06—Synchronising arrangements
    • H04J3/0635—Clock or time synchronisation in a network
    • H04J3/0685—Clock or time synchronisation in a node; Intranode synchronisation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J14/00—Optical multiplex systems
    • H04J14/02—Wavelength-division multiplex systems
    • H04J14/0201—Add-and-drop multiplexing
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q11/00—Selecting arrangements for multiplex systems
    • H04Q11/0001—Selecting arrangements for multiplex systems using optical switching
    • H04Q11/0005—Switch and router aspects
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J14/00—Optical multiplex systems
    • H04J14/02—Wavelength-division multiplex systems
    • H04J14/0201—Add-and-drop multiplexing
    • H04J14/0202—Arrangements therefor
    • H04J14/0204—Broadcast and select arrangements, e.g. with an optical splitter at the input before adding or dropping
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J14/00—Optical multiplex systems
    • H04J14/02—Wavelength-division multiplex systems
    • H04J14/0201—Add-and-drop multiplexing
    • H04J14/0215—Architecture aspects
    • H04J14/0219—Modular or upgradable architectures
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J2203/00—Aspects of optical multiplex systems other than those covered by H04J14/05 and H04J14/07
    • H04J2203/0001—Provisions for broadband connections in integrated services digital network using frames of the Optical Transport Network [OTN] or using synchronous transfer mode [STM], e.g. SONET, SDH
    • H04J2203/0003—Switching fabrics, e.g. transport network, control network
    • H04J2203/0005—Switching elements
    • H04J2203/0007—Space switch details
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q11/00—Selecting arrangements for multiplex systems
    • H04Q11/0001—Selecting arrangements for multiplex systems using optical switching
    • H04Q11/0062—Network aspects
    • H04Q11/0071—Provisions for the electrical-optical layer interface
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q11/00—Selecting arrangements for multiplex systems
    • H04Q11/0001—Selecting arrangements for multiplex systems using optical switching
    • H04Q11/0005—Switch and router aspects
    • H04Q2011/0037—Operation
    • H04Q2011/0039—Electrical control
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q11/00—Selecting arrangements for multiplex systems
    • H04Q11/0001—Selecting arrangements for multiplex systems using optical switching
    • H04Q11/0005—Switch and router aspects
    • H04Q2011/0037—Operation
    • H04Q2011/0045—Synchronisation

Definitions

  • the invention relates to an optical network element for switching wavelengths of a wavelength-division-multiplexed signal, with optical receivers and transmitters each designed respectively to receive and transmit a predetermined wavelength, and with a space switching matrix, arranged between the receivers and the transmitters, for selectively switching digital signals contained in the individual wavelengths.
  • the invention further relates to a system comprising an optical network element of this kind and a digital cross-connect which is designed to switch multiplex units multiplexed in a time-division-multiplexed digital signal in accordance with a multiplex hierarchy of a synchronous digital transmission network, and to a digital cross-connect of this kind as such.
  • WDM wavelength division multiplexing
  • DWDM dense wavelength division multiplexing
  • Such optical transmission networks require optical network elements such as add/drop multiplexers which can extract individual wavelengths from the multiplex signal and insert individual wavelengths into a multiplex signal, and optical cross-connects which can switch individual wavelengths between different multiplex signals or also within one multiplex signal.
  • a promising means of fulfilling these objectives consists of the splitting of a received multiplex signal into the individual wavelengths, for example by means of and-pass filtering, and the switching thereof via a space switching matrix.
  • electrical solutions are being developed in which the optical digital signals contained in the individual wavelengths are converted into electrical digital signals in the receiver, switched by an electric space switching matrix, and reconverted into optical digital signals in transmitters.
  • work is also underway on a completely optical switching of the digital signals.
  • a wavelength can be used to transport a digital signal of arbitrary data content and format, such as IP packets, ATM cells or communications signals structured in accordance with the ITU-T recommendations for SDH and SONET.
  • Current transmission networks are mainly SDH and SONET networks. Therefore the transmission of SDH signals will constitute an important application in future WDM networks.
  • These are time-division-multiplexed, frame-structured communications signals in which virtual containers of different hierarchy levels are multiplexed in accordance with a multiplex hierarchy in a payload region of the transport frames and are addressed by a pointer in the header region of the transport frames.
  • Virtual containers contain the actual useful information to be transmitted together with control information for the transmission path in the network.
  • Virtual containers of sizes VC-12 (VC-11 for SONET), VC-2, VC-3 and VC-4 (only in SDH) are specified as hierarchy levels, smaller containers always being multiplexed in larger containers and addressed by a pointer in the header region of the larger containers.
  • the precise structure of the containers and of the transport frame and the different multiplexing possibilities are described in ITU-T G.707 (3/96).
  • SDH and SONET-networks will be referred to in the following as synchronous transmission networks.
  • Digital signals structured in accordance with ITU-T G.707 will be referred to in the following as synchronous communications signals.
  • Such synchronous transmission networks require network elements such as add/drop multiplexers which are capable of extracting or inserting individual virtual containers of different hierarchy levels from/into a synchronous communications signal, digital cross-connects which switch transmission paths by cross-connecting virtual containers, and line- and terminal multiplexers which can terminate transmission paths.
  • network elements such as add/drop multiplexers which are capable of extracting or inserting individual virtual containers of different hierarchy levels from/into a synchronous communications signal, digital cross-connects which switch transmission paths by cross-connecting virtual containers, and line- and terminal multiplexers which can terminate transmission paths.
  • the line interfaces of such network elements must comply with different standardized requirements.
  • the line interfaces should be able to be interrogated and configured via a central management system, that communications signals to be transmitted are scrambled in the line interfaces and received communications signals are correspondingly descrambled in the line interfaces, and that the transmitting lasers are monitored at their output end in respect of function and transmission level.
  • an object of the present invention is to provide an optical network element for a WDM network with which synchronous communications signals can be transported via the WDM network in a simpler and efficient manner.
  • a further object of the invention is to provide a network element for a synchronous transmission network with which synchronous communications signals can be received from an optical network element of a WDM network in a simpler and efficient manner.
  • a further object of the invention is to provide a system comprising such an optical network element and such a network element for a synchronous transmission network.
  • an optical network element for switching wavelengths of a wavelength-division-multiplexed optical signal comprising:
  • a number of optical receivers each connected to the optical input, for receiving one of the wavelengths contained in the optical multiplex signal
  • a space switching matrix arranged between the optical receivers and the optical transmitters, for selectively switching digital signals, received in the individual wavelengths, between the optical receivers and the optical transmitters and
  • At least one further optical transmitter which is likewise connected to the space switching matrix, for generating an optical digital signal, synchronised to a reference clock, with a frame structure which is composed of consecutive transport frames and in which multiplex units are multiplexed in accordance with a multiplex hierarchy in a payload region of each transport frame and are addressed by a pointer in the header region of each transport frame, and where the multiplex units are always embedded in the transport frame such that the pointer value remains unchanged from one transport frame to the next.
  • a network element for a synchronous transmission network for switching multiplex units multiplexed in time-division-multiplexed optical digital signals, wherein the digital signals have a frame structure which consists of consecutive transport frames and in which the multiplex units are multiplexed in accordance with a multiplex hierarchy in a payload region of each transport frame and are addressed by a pointer in the header region of each transport frame comprising:
  • a number of optical receivers each for receiving one of the time-division-multiplexed optical digital signals and for generating an internal digital signal, synchronised to a common reference clock, with a frame structure which consists of consecutive restructured frames and in which the multiplex units are embedded in each of the restructured frames such that the pointer value remains unchanged from one frame to the next,
  • a space-time switching matrix arranged between the optical receivers and the optical transmitters, for selectively switching the multiplex units, contained in the internal digital signals, between the optical receivers and the optical transmitters and
  • At least one opto-electronic converter which is likewise connected to the space-time switching matrix, for converting a received optical digital signal into an electric digital signal, where an input-end optical terminal of the opto-electric converter leads outwards so that via this terminal the network element can be supplied with an optical digital signal, synchronised to the same common reference clock, with a frame structure which consists of consecutive transport frames, where multiplex units contained therein are embedded in each transport frame such that the pointer value remains unchanged from one transport frame to the next.
  • a system comprising an optical network element for switching wavelengths of a wavelength-division-multiplexed optical signal, and a network element for a synchronous transmission network for switching multiplex units of a time-division-multiplexed synchronous digital signal, wherein the optical network element comprises:
  • a number of optical receivers each connected to the optical input, for receiving one of the wavelengths contained in the optical multiplex signal
  • a number of optical transmitters each for generating an optical digital signal with a wavelength assigned to the transmitter, where the optical transmitters are connected at their output end to a common optical output for a wavelength-division-multiplexed optical output signal,
  • a space switching matrix arranged between the optical receivers and the optical transmitters, for selectively switching digital signals, received in the individual wavelengths, between the optical receivers and the optical transmitters and
  • At least one further optical transmitter which is likewise connected to the space switching matrix, for generating an optical digital signal, synchronised to a reference clock, with a frame structure which consists of consecutive transport frames and in which multiplex units are multiplexed in accordance with a multiplex hierarchy in a payload region of each transport frame and are addressed by a pointer in the header region of each transport frame and where the multiplex units are embedded in the transport frames such that the pointer value remains unchanged from one transport frame to the next,
  • the network element for the synchronous transmission network comprises:
  • a number of optical receivers each for receiving one of the time-division-multiplexed optical digital signals and for generating an internal digital signal synchronised to a common reference clock, with a frame structure which consists of consecutive restructured frames and in which the multiplex units are embedded in each of the restructured frames such that the pointer value remains unchanged from one frame to the next,
  • a space-time switching matrix arranged between the optical receivers and the optical transmitters, for selectively switching the multiplex units, contained in the internal data signals, between the optical receivers and the optical transmitters and
  • At least one opto-electric converter which is likewise connected to the space-time switching matrix, for converting a received optical digital signal into an electric digital signal, where an input-end optical terminal of the opto-electric converter leads outwards so that via this terminal the network element can be supplied with an optical digital signal, synchronised to the same common reference clock, with a frame structure composed of consecutive transport frames, where multiplex units contained therein are embedded in each transport frame such that the pointer value remains unchanged from one transport frame to the next,
  • FIG. 1 illustrates an optical add/drop multiplexer for switching wavelengths of a wavelength-division-multiplexed multiplex signal
  • FIG. 2 illustrates a digital cross-connect for a synchronous transmission network for switching multiplex units of a time-slot-multiplexed communications signal
  • FIG. 3 illustrates a system comprising the optical add/drop multiplexer according to FIG. 1 and the digital cross-connect according to FIG. 2.
  • WDM networks arbitrary digital signals are transmitted in transparent manner. For this purpose each signal to be transmitted is allocated one wavelength and the individual wavelengths are wavelength-division-multiplexed to form a multiplex signal.
  • optical network elements are required. The granularity which can be switched by an optical network element of this kind is to be one wavelength.
  • a main application of such WDM networks at least in the next few years, will consist of the transmission of synchronous communications signals from a synchronous communications network (SDH or SONET).
  • An electric switching matrix is generally used in optical network elements. If an SDH network element is now to be connected to an optical network element, some functions of the line interface of the SDH network element could actually be performed in the optical network element. However, the large bandwidth of the digital signals to be switched imposes a spatial restriction, i.e. only short distances of a few meters can be bridged by electric lines. Therefore optical network element and SDH network element are optically connected.
  • a basic principle of the invention is that, in the case of a connection between an optical network element and a SDH network element, although the line interface of the SDH network element is logically allocated to the SDH network element, it is physically allocated to the optical network element. It is then possible to use a favourable internal optical interface between the two network elements.
  • An optical network element can be roughly divided into two main assemblies:
  • the core assembly is a broadband switching matrix, for example for 10 Gbit/sec-signals, together with electrical connecting means such as line driver circuits and line receiver circuits.
  • the second group of assemblies comprises the optical I/O assemblies (I/O: input/output), i.e. optical receivers and optical transmitters.
  • FIG. 1 illustrates an optical add/drop multiplexer OADM as an exemplary embodiment of an optical network element.
  • This has an optical input which is connected to an optical waveguide via which a wavelength-division-multiplexed optical multiplex signal F 1 is received.
  • the optical input is connected via a splitter to a plurality of optical receivers OR 1 -ORN in each case provided for one wavelength.
  • Each of the optical receivers receives an allocated wavelength and converts an optical digital signal, contained in this wavelength, into an electrical digital signal.
  • the optical receivers are each electrically connected to a line receiver LR 1 -LRN. 50 Ohm coaxial cable interfaces are used for the electrical connections.
  • the OADM also comprises an electric space switching matrix SSM which is used for the selective switching of the received digital signals.
  • the line receivers LR 1 -LRN are connected to the inputs of the space switching matrix SSM.
  • Line drivers LD 1 -LDN are connected to the outputs of the matrix.
  • the matrix capacity of 128 ⁇ 128 is sufficient for four-fibre rings (one fibre for each direction and one redundant fibre for each direction) with 32 wavelengths per fibre.
  • the matrix switches the electric digital signals in bit-rate-transparent manner for bit rates between 100 Mbit/sec and 10 Gbit/sec.
  • higher-speed switching atrices capable for example of switching digital signals up to 40 Gbit/sec, will undoubtedly also be used for applications which require higher bit rates.
  • the switching matrix also has broadcast capability, i.e. each input can be connected simultaneously to a plurality of outputs so that an input signal can be switched simultaneously to a plurality of outputs (broadcast switching).
  • Each of the line drivers LD 1 -LDN is connected to an optical transmitter OT 1 -OTM, OTP.
  • the optical transmitters OT 1 -OTM in each case generate an optical digital signal with a wavelength assigned to the transmitter.
  • the output level of the optical signal is monitored to ensure that the optical signals are transmitted over long fibre links of at least 80 km length.
  • the optical transmitters OR 1 -OTM are connected via a coupler to an output of the OADM. This output is connected to an optical waveguide via which a wavelength-division-multiplexed multiplex signal (FO) is transmitted.
  • FO wavelength-division-multiplexed multiplex signal
  • a further optical transmitter OTP is connected to the switching matrix SSM.
  • This further optical transmitter OTP is designed for synchronous communications signals and performs functions typical of a line interface of a SDH network element.
  • the transmitter reclocks the synchronous communications signal to a reference clock and restructures the transport frames contained in the communications signal.
  • multiplex units which are internested in the payload region of each transport frame in accordance with the SDH multiplex hierarchy and are addressed by a pointer in the header region of each transport frame, are always embedded in the restructured transport frames such that the pointer value remains unchanged from one transport frame to the next. This serves to compensate pointer justifications, which are typically performed in synchronous transmission networks, for correcting clock differences of the network elements of the transmission network.
  • a proprietary frame format also employed as internal frame format in SDH network elements, is used for the restructured frames. Therefore an identifier is attached to the communications signal, as well as check bits facilitating error checking. Then, by means of a simple laser diode without level monitoring, the thus generated, restructured communications signal is transmitted as optical digital signal via another connected fibre to another output of the optical OADM. As a non-standard signal format is transmitted, this further transmitter OTP is a proprietary output.
  • FIG. 2 illustrates a digital cross-connect DXC as an exemplary embodiment of a network element of a synchronous transmission network.
  • the DXC has a plurality of optical receivers L 12 -L 1 N, a plurality of optical transmitters LO 1 -LON and a space-time switching matrix STSM.
  • the space-time switching matrix STSM is a N ⁇ N matrix with N inputs and N outputs.
  • the switching matrix STMS can have the form of a three-stage Clos matrix.
  • Opto-electronic converters OE 1 -OEN are connected to the inputs of the switching matrix STSM, and the outputs of the switching matrix STSM are connected to electro-optical converters EO 1 -EON.
  • the matrix represents a modular unit which is switched with interface modules such as transmitters and receivers via simple internal optical connections.
  • the matrix itself preferably is likewise of modular construction and therefore easily expandable.
  • the DXC is therefore of modular construction in respect of the matrix and interfaces, i.e. the transmitter and receiver circuits, and therefore can easily be expanded.
  • the functionality of the DXC is highly dependent upon the functionality made available by the interface circuits.
  • the individual modules are connected by internal optical connections with a length of up to 200 m.
  • the switching matrix has a switching capacity of 2000 STM-1 equivalents, but can be expanded to a switching capacity of up to 16,000 STM-1 equivalents.
  • the configuration of matrix and interface circuits is software-controlled.
  • the receivers L 12 -L 1 N are each connected to an optical waveguide via which synchronous communications signals F 12 -F 1 N are received from the synchronous communications network to which the DXC is connected.
  • the communications signals F 12 -F 1 N are time-division-multiplexed, optical, digital signals and have a frame structure which consists of consecutive transport frames and in which multiplex units of different sizes are multiplexed in accordance with a multiplex hierarchy in a payload region of each transport frame.
  • the multiplex units are referred to as virtual containers and contain the useful information which is actually to be transmitted as well as control information for the transmission path in the network.
  • Virtual containers of the sizes VC-12 (VC-11 for SONET), VC-2, VC-3 and VC-4 (only in SDH) are specified as hierarchy levels, smaller containers always being multiplexed in larger containers and addressed by a pointer in the header region of the larger containers.
  • the largest virtual container (VC-4 in the case of SDH, in each case three VC-3s in the case of SONET) is addressed by a pointer in the header region of each transport frame.
  • Each of the receivers L 12 -L 1 N serves as a receiving-end line interface to the synchronous communications network and performs standardized functions, such as the descrambling of the received communications signals F 12 -F 1 N, and control- and configuration functions at the request of a central management system. Additionally a restructuring of the received transport frames into an internal frame format is performed in each receiver. For this purpose, the received communications signals are reclocked to an internal reference clock and the virtual containers contained in the received transport frames are packed into fixed columns of a new internal frame which do not change from one frame to the next. This also means that no change occurs in the pointer value of the pointer in the frame header of the restructured frames from one frame to the next.
  • Each of the receivers LR 1 -LRN is connected to one of the opto-electronic converters OE 2 -OEN via an internal optical connection, which in the exemplary embodiment is to be no longer than 200 m, and via this connection transmits the restructured synchronous communications signals in the internal frame format to the switching matrix STSM.
  • the switching matrix STSM is connected to the optical transmitters LO 1 -LON.
  • each of the electro-optical converters EO 1 -EON is in each case connected via an internal optical connection to one of the optical transmitters LO 1 -LON.
  • Each of the transmitters LO 1 -LON serves as a transmitting-end line interface into the synchronous communications network and, in the same way as the receiving-end line interfaces, performs standardized functions, such as the scrambling of the communications signals FO 1 -FON to be transmitted, and control- and configuration functions at the request of the central management system.
  • the digital signals received by the switching matrix STSM which are structured in the internal frame format, are converted into the frame format prescribed for SDH.
  • the optical transmitters LO 1 -LON are each connected to an optical waveguide via which the thus converted digital signals FO 1 -FON are transmitted into the synchronous transmission network.
  • the DXC is provided with a further input which is not connected to an optical receiver of the above described type but is directly connected to one of the opto-electronic converters OE 1 .
  • An optical fibre is connected to this input, via which optical fibre an already restructured, synchronous communications signal FP is received from another network element.
  • the input-end terminal of the opto-electrical converter OE 1 is connected as input to the exterior of the DXC so that via this input the DXC can be supplied with the optical communications signal FP already synchronised to the same internal reference clock.
  • the communications signal FP has a frame structure which consists of consecutive transport frames, where the virtual containers internested in the frames are embedded in fixed columns of each transport frame, i.e. columns which remain the same from one frame to the next, and the pointer value thus remains unchanged from one transport frame to the next.
  • this further input is a proprietary input.
  • FIG. 3 illustrates the cooperation of the optical add/drop multiplexer OADM in FIG. 1 and of the digital cross-connect DXC in FIG. 2.
  • the proprietary output OTP of the OADM is connected to the opto-electronic converter OE 1 , i.e. the proprietary input, of the DXC via a simple optical fibre.
  • the communications signal FP which is transmitted via this fibre from the OADM to the DXC, is already synchronised to the internal clock of the DXC and restructured in order to compensate pointer justifications, the communications signal can be used directly, without preprocessing, as input signal for the switching matrix STSM of the DXC. All the functions of a line interface which must be performed in the DXC are already implemented at the transmitting end in the OADM.
  • both network elements OADM and DXC are connected to the central management system CS of the synchronous transmission network.
  • a clock connection not shown in FIG. 3 extends between the network elements, for example via a 2 MHZ interface of the two devices.
  • the interface OTP of the OADM is supplied with a reference clock by the DXC.
  • the interface OTP is thus synchronised to the reference clock of the DXC, while the other outputs of the OADM are synchronised to an intrinsic clock—generally the clock of the input signal which is switched to the relevant output via the space switching matrix SSM. Consequently the interface OTP of the OADM is coordinated with the DXC both logically and in terms of synchronisation.
  • FIG. 3 illustrates the interconnection of the OADM according to the invention and the DXC.
  • the two network elements can also be combined to form one system and commonly installed.
  • the system can also consist of one single network element in which the OADM and the DXC are integrated.
  • this integrated network element can be equipped with a common power supply, a common control terminal and a common control computer.
  • the integrated network element can also be constructed as a modular system composed of sub-components such as interface cards and matrix modules and installed in a common rack.

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Time-Division Multiplex Systems (AREA)
  • Optical Communication System (AREA)
  • Use Of Switch Circuits For Exchanges And Methods Of Control Of Multiplex Exchanges (AREA)
  • Data Exchanges In Wide-Area Networks (AREA)
US09/810,226 2000-03-20 2001-03-19 Optical network element Abandoned US20010055135A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE10013489A DE10013489A1 (de) 2000-03-20 2000-03-20 Optisches Netzelement
DE10013489.0 2000-03-20

Publications (1)

Publication Number Publication Date
US20010055135A1 true US20010055135A1 (en) 2001-12-27

Family

ID=7635433

Family Applications (1)

Application Number Title Priority Date Filing Date
US09/810,226 Abandoned US20010055135A1 (en) 2000-03-20 2001-03-19 Optical network element

Country Status (4)

Country Link
US (1) US20010055135A1 (de)
EP (1) EP1137311A2 (de)
JP (1) JP2001333440A (de)
DE (1) DE10013489A1 (de)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040131359A1 (en) * 2002-08-09 2004-07-08 Shigeyuki Yamashita Data transmission method and data transmission apparatus
US20050254527A1 (en) * 2004-05-14 2005-11-17 Alcatel Network element with multistage lower order switching matrix
WO2007006177A1 (fr) * 2005-07-13 2007-01-18 Zte Corporation Procédé et système permettant d’obtenir un multiplexage croisé et transparent conformément au protocole générique de verrouillage de trames
US20090028577A1 (en) * 1999-07-15 2009-01-29 Fujitsu Limited Optical repeater converting wavelength and bit rate between networks
US20120314797A1 (en) * 2011-06-09 2012-12-13 Andrew Llc Distributed Antenna System Interface for Processing Digital Signals in a Standardized Format

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10208747A1 (de) * 2002-02-28 2003-09-25 Siemens Ag Universeller Crossconnector

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6195367B1 (en) * 1997-12-31 2001-02-27 Nortel Networks Limited Architectural arrangement for bandwidth management in large central offices
US6333799B1 (en) * 1997-01-07 2001-12-25 Tellium, Inc. Hybrid wavelength-interchanging cross-connect
US6452931B1 (en) * 1994-02-28 2002-09-17 Sprint Communications Company L.P. Synchronous optical network using a ring architecture

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6452931B1 (en) * 1994-02-28 2002-09-17 Sprint Communications Company L.P. Synchronous optical network using a ring architecture
US6333799B1 (en) * 1997-01-07 2001-12-25 Tellium, Inc. Hybrid wavelength-interchanging cross-connect
US6195367B1 (en) * 1997-12-31 2001-02-27 Nortel Networks Limited Architectural arrangement for bandwidth management in large central offices

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20090028577A1 (en) * 1999-07-15 2009-01-29 Fujitsu Limited Optical repeater converting wavelength and bit rate between networks
US7522843B2 (en) * 1999-07-15 2009-04-21 Fujitsu Limited Optical repeater converting wavelength and bit rate between networks
US20040131359A1 (en) * 2002-08-09 2004-07-08 Shigeyuki Yamashita Data transmission method and data transmission apparatus
US7454142B2 (en) * 2002-08-09 2008-11-18 Sony Corporation Data transmission method and data transmission apparatus
US20050254527A1 (en) * 2004-05-14 2005-11-17 Alcatel Network element with multistage lower order switching matrix
US8018927B2 (en) * 2004-05-14 2011-09-13 Alcatel Lucent Network element with multistage lower order switching matrix
WO2007006177A1 (fr) * 2005-07-13 2007-01-18 Zte Corporation Procédé et système permettant d’obtenir un multiplexage croisé et transparent conformément au protocole générique de verrouillage de trames
US20120314797A1 (en) * 2011-06-09 2012-12-13 Andrew Llc Distributed Antenna System Interface for Processing Digital Signals in a Standardized Format
US9735999B2 (en) * 2011-06-09 2017-08-15 Commscope Technologies Llc Distributed antenna system interface for processing digital signals in a standardized format
US11310092B2 (en) 2011-06-09 2022-04-19 Commscope Technologies Llc Distributed antenna system interface for processing digital signals in a standardized format

Also Published As

Publication number Publication date
DE10013489A1 (de) 2001-09-27
JP2001333440A (ja) 2001-11-30
EP1137311A2 (de) 2001-09-26

Similar Documents

Publication Publication Date Title
US6532320B1 (en) Equipments, transpondor and methods for optical fiber transmission
JP4159359B2 (ja) デジタル交差接続
US7580635B2 (en) Method, apparatus and system for optical communications
JP5132778B2 (ja) 光ネットワークシステム、光冗長切替え装置およびｗｄｍ装置
US6570685B1 (en) Node for optical communication and wavelength-division multiplexing transmission apparatus having a ring structure composed of the same nodes
JP3092521B2 (ja) 通信ネットワークノード装置、光通信ネットワークノード装置、信号監視方式、及び、通信ネットワーク
US7280758B2 (en) Optical multi-ring network for burst data communication
US6094442A (en) Optical path signal termination equipment
KR100582093B1 (ko) 광 전달망 시스템에서의 광 감시 채널 프레이밍 장치 및그 방법
US6594047B1 (en) Apparatus and method for providing optical channel overhead in optical transport networks
US20020135835A1 (en) Optical traffic grooming
US20010055135A1 (en) Optical network element
US20020080442A1 (en) Optical cross-connect for optional interconnection of communication signals of different multiplex levels
US7016378B1 (en) Method and system for automatically provisioning an overhead byte
JP3551115B2 (ja) 通信ネットワークノード
US20020081058A1 (en) Optical cross-connect for optional interconnection of communication signals of different multiplex levels
JP2001007829A (ja) 光監視チャネル転送装置
US20020080441A1 (en) Optical cross-connect for optional interconnection of communication signals of different multiplex levels
WO1999018679A1 (en) An optical network with protection path for failure recovery
EP0957603B1 (de) Integrierte Leitungssyteme und Cross Connect
Johnson et al. Evolution of optical core networks
KR20010078510A (ko) 다수 ｓｔｍ-1급 ａｔｍ국간 전송 ｗｄｍ링크접속장치
Shin et al. Optical Supervisory Mechanisms in Next-gen OTN for Enhanced Maintenance Functions
Johnson et al. Evolution of optical core networks
WO2001030006A9 (en) Communication network for transmitting and restoring an optical signal

Legal Events

Date Code Title Description
AS Assignment

Owner name: ALCATEL, FRANCE

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:SIGLOCH, RAINER;REEL/FRAME:012013/0704

Effective date: 20010322

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION